The Association With Growth And Body Composition Traits And Analysis Of Ligand Binding Properties Of Chicken Liver Basic Fatty Acid-binding Protein And Liver Fatty Acid-binding Protein

Fatty acid binding proteins (FABPs), a group of small molecular weight proteins having highbinding affinities for fatty acids, belongs to a superfamily of lipid-binding proteins, where they serve anessential role in the modulation of lipids metabolism. This study was designed to investigate two typesof fatty acid-bingding proteins (Lb-FABP and L-FABP) in chicken liver. The14thgenerationpopulations from NEAU broiler lines divergently selected for abdominal fat content (NEAUHLF) andthe Northeast Agricultural University F2(NEAUF2) resource population were used. DNA sequencingand Sequenom MassARRAY methods were developed to detect polymorphisms of the two genes.Differences of allele frequencies between fat line and lean line in the14thgeneration, and associationsof the two genes polymorphisms with growth and body composition traits were investigated. And theligand binding property of chicken Lb-FABP and L-FABP were determined. The main results were asfollows:(1) Based upon sequencing，four SNPs of Lb-FABP gene were detected, including three SNPsin5’ flanking region and one SNP in3’ flanking region. According to the SNPs of the Lb-FABP gene inthe chicken genomic databases (www.genome.ucsc.edu) and the results in the current study,seventeen SNPs of L-FABP gene were detected, including sixteen SNPs in5’ flanking region and oneSNP in coding region. According to the SNPs of the L-FABP gene in the chicken genomic databases(www.genome.ucsc.edu) and the SNPs detected in the current study, five SNPs (SNP1-SNP5) in the Lb-FABP gene and fifteen SNPs (SNP6-SNP20) in the L-FABP gene, were selected for genotyping. Thetwenty SNPs were named according to the nomenclature system.(2) In the NEAUF2population, the Lb-FABP SNP1was related to BW (BW0, BW6, BW9, BW10and BW11), CW, PrW and%PrW (P<0.05); SNP2was related to BW (BW0, BW6, BW9, BW10,BW11and BW12), CW, PrW and%PrW (P<0.05); SNP3was related to BW (BW3, BW6, BW7, BW8,BW9, BW10, BW11and BW12)(P<0.05). In the NEAUHLF population, the Lb-FABP SNP1wasrelated to BW(BW3and BW5)(P<0.05); SNP2was related to BW (BW3and BW5)and%AFW(P<0.05); SNP3was related to BW3, AFW and%AFW(P<0.05).(3) In the NEAUF2population, the diplotypes of Lb-FABP gene was related to BW (BW6, BW7,BW9, BW10, BW11, and BW12)(P<0.05). In the NEAUHLF population, the diplotypes of Lb-FABP gene was related to BW(BW3, BW5)(P<0.05).(4) In the NEAUF2population, the L-FABP SNP15was related or significantly related to BW(BW7, BW8, BW9, BW10, BW11and BW12)(P<0.05, P<0.01). In the NEAUF2population, the L-FABP SNP7, SNP8,SNP19and SNP20was significantly related to TeW and%TeW(P<0.01).(5) The fluorescent probe1-anilinonaphthalene8-sulfonic acid (1,8-ANS) has been used to bind toLb-FABP and L-FABP proteins, respectively. L-FABP exhibited the higher affinity probe bindingapparent dissociation constants (Kd) of1.95μM， while Lb-FABP bound1,8-ANS with apparentdissociation constants of4.71μM.(6) In order to quantitate the palmitic acid, arachidomic acid, oleic acid, cholic acid and retinoidacid binding specificity and affinity of Lb-FABP and L-FABP, a competition assay was developed todetect the ability of various lipid molecules to displace bound1,8-ANS from the binding cavity. Theresults revealed that there were the biggest activity of Lb-FABP binding to retinoid acid （Ki=0.30）and the biggest activity of L-FABP binding to oleic acid（Ki=1.56）.